Dynamo-electric machine



March 12, 1940.

E. R. KNIGHT ,193,408

DYNAMO-ELECTRIC MACHINE Filed March 10, 195-, 2 Sheets- Sheet 1 7 a w 7l5 3 March 12, 1940.

E, R. KNIGHT DYNAMO-ELECTRIC MACHINE Filed March 10, 1937 2 Sheets-Sheet2 ll W L-J ill Patented Mar. 12, 1940 UNITED STATES PATENT OFFIEDYNAMO-ELECTRIC MACHINE Application March 10,

21 Claims.

This invention relates in general to dynamoelectric machines, and it hasmore particular relation to such machines of the ventilated type as aredesigned or intended for use in dust or lint laden atmospheres, as inthe case of motors for operation in textile mills, where the lint in theair drawn over the parts of the motor structure clogs the ventilatingpassages and builds up a coating on parts of the motor structure, whichinterferes with the ready dissipation of heat from these parts to theventilating air.

The matter of maintaining dynamo-electric machines, particularlyelectric motors, ordinarily of the induction type, used for drivingmachinery in textile mills and like plants, where the air contains aconsiderable amount of lint or dust, in a clean and relatively cooloperating condition without excessive maintenance expense andinconvenience, has long been a considerable problem. In order tomaintain an ordinary ventilated motor in eflicient operating conditionunder such circumstances, it must be taken out of service at frequentintervals to permit a thorough cleaning and removal of accumulated lintand dust; and this operation, in addition to being a decidedinconvenience and often resulting in rendering the driven machineryidle, is a considerable item of maintenance expense.

The present invention contemplates a design and construction ofdynamo-electric machine of the ventilated type, wherein effectiveprovisions are made for preventing or inhibiting the lodging ofparticles of lint or dust from the stream. of ventilating air upon partsof the motor with which the moving current of ventilating air contactsand wherein ready inspection and access to the ventilating passages andparts of the motor, without removal of the machine from service, ispermitted. And through the present invention, it is possible to securethese desirable results with a design and a construction of machinewhich is extremely simple and which permits ready assembling anddisassembling of the motor, and through which, because of thesubstantial freedom of obstructions in the ventilating passages, themachine is practically selfcleaning during regular service, by reason ofthe forced passage therethrough of a substantially unobstructed flow ofair.

Certain advantages of the present invention are secured by independentlysupporting the stator and rotor of the machine on the machine base, andby providing a form of support for the stator which insures a large areaof ventilating space about the stator, and particularly 1937, Serial No.130,025 (01. 171-252) about the lower portion thereof, where greatliability to obstruction of air passages by lint and dust has heretoforeexisted in prior designs, with minimum obstruction to the fiow ofventilating air and minimum tendency tocatch and hold particles of lintor dust, and in providing end closures of a character that insuremaximum iacility for inspection and cleaning of the machine while inservice and for ready disassembly of the machine.

It is an object of the present invention to provide a dynamo-electricmachine of the ventilated type of improved design and construction andembodying features facilitating effective cooling of the machine andmaintaining it in clean condition in service.

It is a further object of the present invention to provide an improveddesign and construction of dynamo-electric machine of the ventilatedtype providing minimum obstruction to the passage of ventilating airacross heated surfaces of the stator of the machine and the discharge ofheated air therefrom, and maximum ready accessibility to interior partsof the machine.

It is a further object of the present invention to provide an improveddesign and construction of dynamo-electric machine of the ventilatedtype embodying a stator elementremovably supported only at spaced pointson a base and end housings supported on the base independently of thestator, providing ventilating air passages across the entire peripheryof the stator element with minimum obstruction to the flow of theventilating air.

The above and other objects and advantages attained through the presentinvention will be apparent from the description and drawings herein,disclosing embodiments of features of the invention, and will be moreparticularly pointed out in the claims.

In the drawings:

Figure 1 is a view in vertical section, in the plane of the line II ofFig. 2, with portions shown in elevation, of a dynamo-electric machineembodying features of the present invention;

Fig. 2 is a sectional view, in the plane of the line II-II of Fig. 1;

Fig. 3 is a fragmental section in the plane of the line IIIIII of Fig.2, showing a detail;

Figs. 4 and 5 are views in broken section and elevation, respectively,of a somewhat modified form of the machine of Figs. 1 and 2, the sectionof Fig. 5;

Figs. 6 and 7 are views in broken section and elevation, respectively,of a modified form of the machine of Figs. 1, 2, 4 and 5, as to thestator mounting thereof, the section of Fig. 6 being in the plane of theline VTVI of Fig. '7; and

Fig. 8 is a fragmental view similar to Fig. 6, showing a furthermodified form of stator mount- The invention is applied, in theembodiments thereof illustrated in the drawings, to an induction motorsuch as is particularly applicable for driving textile machinery.

Considering Figs. 1 and 2 more particularly, the rotor 2'. may be ofconventional design, embodying a core 3 having slots at or adjacent itsperiphery and in which are disposed conductor bars of a squirrel cagewinding, the core being suitably mounted, as by means of a key, and heldagainst longitudinal movement, on a shaft 4. A ventilating fan 5including a plurality of blades, of the substantially axial inflow andradial discharge type, is provided at each end of the rotor core.

The active stator (i of the motor is made up of a plurality of annularlaminae pressed and held together by end heads or clamping rings 1 toform the core 3, the laminae being secured together and to the end headsby bolts or rods riveted or otherwise secured in conventional manner. Inthe form shown, the end heads 1 are provided with spaced aperturedperipheral enlargements El, and the ends of clamping bolts ill, passingthrough these peripheral enlargements and corresponding peripheralenlargements ll of the stator core laminae, are secured to the end heads6 by riveting, welding, or like method, to provide a compact and solidstructure. The outer periphery of the end heads, with the peripheralenlargements thereof, are preferably rounded over in smoothcurves, asindicated inFigs. l and 3, so as to easily merge into the outerperiphery of the adjacent portions of the core, thus eliminatingobstructions to flow of ventilating air along the surfaces and. avoidingpockets in which lint or dust, carried by the ventilating air, mightlodge.

A conventional form of distributed type winding I2 is disposed andsecured in slots at the inner periphery of the stator core, the endprojecting turns of the winding being enclosed within relatively stiff,thin protecting shields l3, preferably of insulating composition, ofchannel or V-shape in cross section, with the open edges at the sideadjacent the stator core. The inside surface of each protecting shieldconforms to and fits quite closely about the outline of the end turns,and the shields are held in position by having the radially outer edgesthereof secured to the adjacent end head, as by cementing such edge tothe adjacent face of the end head, and the inner edge of the shield ispreferably cemented to the adjacent end laminae of the core andpreferably to adjacent portions of the radially inner surface of theextending end turns. Through the arrangement described, the endprotecting shields provide an enclosing housing for the end turns of thewinding, with smooth and easily curving exterior which eliminatespockets andobstructions to the ventilating air stream, as well asprotecting the windings from an accumulation of lint and dirt thereonwhich would retard the ready dissipation of heat from the windings; andthe material utilized in these protective shields, as well as thereduced thickness thereof, are such as not to offer any appreciablehindrance to the ready dissipation of heat from the windings to theouter surfaces of the shields.

Each end head is provided at its lower portion with two supporting lugsor projections 15, one at the rear and one at the front side of thestator, shown as extending laterally from the end heads, and disposedwith their lower or seating surfaces arranged in substantially the sameplane, these lugs being disposed substantially equidistant from thevertical central longitudinal plane of the stator. These supporting lugsare provided with vertical, preferably threaded, apertures.

A base I! is provided, the same having supporting feet if! at its lowerside and raised projections or pedestal-like supports I9 suitably spacedand disposed. to constitute seats on which the supporting lugs 15 of thestator may seat and the stator may thereby be suitably positionedrelative to the base.

The body portion of the base comprises a com tral basin-like portion 2|and outwardly extending and upwardly curving end portions 23constituting, along with the annular frame-like element 24 extendingupwardly therefrom and laterally clear of the stator, portions of endhousings or closures of the machine, these annular frame portions 24also serving, as described hereinafter, as supports for bearings for therotor shaft 4. As will be apparent from the drawings, with thesesupporting lugs I5 of the stator properly seated on the spaced seatingprojections iii of the base, the stator is spaced at all points from thebase to a substantial degree, except at the seating projections 19, thusproviding enlarged passages 25 between the base and the under side ofthe stator; and the assembled stator may be readily withdrawn, in asubstantially vertical direction, from its operative position on thebase and between the end frames 24, to a point outside of the base andend frames, for any purpose, such as inspection or repair of the statorwindings. And the axial dimension of the assembled stator may beslightly greater than the minimum axial distance between the upperportions of the end frames 24 and still permit the substantiallyvertical removal of the stator and its insertion to operative positionon the base, in this case the substantial space between the end shieldsI3 of the stator and the end frames permitting the necessary tilting ofthe stator to permit its movement between the upper portions of the endframes.

Particularly where it is contemplated that cooling air will be forcedabout the exterior of the stator from both axial sides toward thecentral portion thereof, as is contemplated in connection with themachine illustrated, the front edge, as viewed in Fig. 1, of the base,is thoroughly open to the surrounding atmosphere, as indicated at 26,between the adjacent seating pedestals 19.

An annular bearing support 28 is removably mounted in position in eachof the annular supporting frame portions 24 carried by the endextensions of the base. This bearing support comprises an outer rimportion 29 seated preferably with a machined fit, in the supportingframe, and being held in fixed position in the frame by one or moreholding screws 30. The diameter of the opening in the end frames inwhich the bearing supports fit is greater than the maximum diameter ofthe rotor so as to permit removal or insertion of the latter through oneof these openings when the corresponding bearing support is removed.Radially within the rim 29 and spaced therefrom is a bearing housingproper 3|, the latter being united to they rim 23 by circumferentiallyspaced ribs 32, the spaces between the ribs being of sufilcient crosssectional area to provide an axial inlet for ventilating air currents tobe supplied for cooling the machine. Within the housing 3| is mounted aconventional form of bearing 34, indicated as being of the ball type andcomprising a series of bearing balls disposed in a race fixed inposition in the bearing housing and cooperating with a complementaryrace held in posi tion on the shaft 4 in suitable manner, as by means ofa nut or collar threaded on the shaft. A sealing device 35 forlubricating material is formed integral with the bearing housing at theaxially inner side thereof, the shaft 4' passing therethrough in desiredfluid-tight sealing engagement therewith. The bearing housing at theleft hand end of the machine may be closed by a removable end cap 35,and the bearing housing at the right hand end of the machine may have aremovable annular sealing device 31 through which the shaft 4 passes inefi'ective fluid sealing relation therewith.

The rim 29 is provided with an integral annular extension 33 at itsinner side projecting toward the rotor 2, but inclined slightly towardthe axis of the motor, to a point adjacent the blades of the fan 5, thisannular extension serving as a shield or guide defining an inlet passagefrom the apertures between the ribs 32 of the bearing support to the fan5; and this shield, in conjunction with the radially inner side of theprotecting shield 13, also defines the passage from the discharge edgeof the fan toward the end housing frame 23, 24 carried by the base.

The stator 5 is held in desired operative position on the base I! bymeans of threaded bolts 4| passing upwardly through apertures in theseating pedestals or supports l9 and threaded into the threadedapertures of the supporting projections or lugs on the end heads I, thebolts being threaded home to desired firm securing position. In order toinsure proper axial alinernent of the stator and rotor and the desireduniform air gap between these parts, one or more shims, indicated at 42,may, if necessary, be disposed between the seating faces of thesupporting pedestals IQ of the base and the supporting lugs I5 of thestator. With the stator adjusted to and secured in desired operativeposition, the parts may, if desired, be definitely held in this positionin any suitable manner.

The end housing portions 23 integral with the base are provided withsupporting ledges, indi-' cated at A5, at their forward and rear sides,and the annular end housing frames 24 extending vertically from theportions 23, are each formed with an external shouldered seat, indicatedat 46. A removable and slightly flexible shield or closure element 4! ofgenerally are shape has its lower ends or edges seated at the front andrear led, .s 45 with its axially outer edge portion. seated on theshouldered seat 46 of the end head 24. This shield 4! preferablyslightly enlarges, and may be slightly bell shaped, toward its axiallyinner edge, and the dimensions of the parts are such that this shield orclosure element is spaced from the outer surface of the protectingshield $3 to substantially the same extent as the lower portion 23 ofthe end housing and. the base ll is spaced from the lower side of theshield and core' The removable closure element '27 may be secured indesired operative position by means of bolts 48, having a removable bailconnection to hooks on the lower portions of the closure and fitting inapertures in the ledges 45 on the housing portions 23 integral with thebase; and an adjustable locking nut 49 serves, when the upper bail endof the bolt is in engagement with its cooperative hook on the lower endof the closure element, to draw the latter down into and hold the same 7in desired secure seating and sealing arrangement on the end housingframe, the locking nut 4!) bearing on the under side of the ledge 45directly or through the intermediary of a bearing washer.

With the parts assembled in the manner described, the stator core andwindings are spaced to a substantial degree from the detachable closureelements ll and the base, with its integral end housing portions 23, 24,except at four spaced points where the stator is supported on the base.There is thus provided a substantially unobstructed and clear passage-orpath for ventilating air from the inlet, between the ribs 32 of thehearing support, to the fans 5, about the end turns of the stator, tothe discharge from the space between the outer surface of the stator andthe removable closure elements 41, and the base H, at the lower side ofthe machine.

In the operation of this embodiment of the invention, air is dravm intothe machine through the openings between the ribs 32 of the hearinghousing support and is guided by the shield or guide 3-8 to the fans 5,and is discharged from the fans in contact with the protecting shieldsE3, to permit ready removal of heat therefrom, and is guided by theradially outer surface of the guides t3 and the inner surfaces of theadjacent end head portions 23, and the base Ill and removable closureelements 4'1, discharg ing substantially axially therefrom across theouter periphery of the stator core in intimate heat dissipatingengagement therewith, before finally discharging to the surroundingatmosphere. The cooling air passing over the outer surfaces of theprotecting shields iii and the stator core at the lower side of themachine is eventually turned at right angles and discharged over theopen front and rear edges of the central portion of the base.

In order to reduce to a minimum the imped- .ing effect to the passage ofair the supporting lugs l5 on the stator and the seating projections 51on the base, the outer surfaces of these lugs or projections arepreferably of easily rounded shape to avoid the formation of pockets.

As will be apparent, the design of the several parts includes theprovision of continuous air passages from the air inlet to the machineto the air discharge therefrom, without the pres-' ence of anyappreciable projections or pockets which would catch. and hold lint ordirt carried by the stream of cooling air and permit the building up ofcoverings of lint and dirt which would reduce the heat dissipation fromthe heated surfaces, and likewise reduce the effective size of theventilating passages, the design be ing such as to be practicallyself-cleaning in service, in that any lint or dust with which thecooling air may be laden is carried along through the ventilatingpassages and discharged from the machine while still suspended in thecooling air.

It will be apparent that the removable end closures ll may be detacheremoved from perative position at any timaleaving the machine almosti'ully'open to inspection as to the. condition of the ventilatingpassages, and this without removing the motor from active service.

In case an intimate inspection or repair 'of the motor is desired, thebearing supports, with the bearings therein may be removed, afterremoval of one of the securing nuts which hold the hearing in positionon the shaft. And with one or both of the bearing housing supportsremoved,

the rotor with the shaft on which it is mounted may be readily removedendwise through one of the 'end head frames 24, the diameter of theopening in the end frame being greater than the diameter of the rotorcore. Or the bearing supports may be removed with the shaft andbearings. The matter of reassembling the machine, by inserting the rotorthrough the opening in. the end frame- M- will be fully apparent fromthe description hereinabove as to disassembling the machine. If it isdesirable to inspect or repair the stator windings while the rotor isremoved from the supporting structure, the stator may be drawn upwardlyfrom the space between the end frames, and thereafter replaced inoperative position, as will be apparent from the descriptionhereinabove.

In Figs. and 5, a modified form of stator supporting means for themachine of Fig. 1 is shown. As indicated, the supporting portions of thestator, instead of being in the form of lugs 95 on the end heads, asshown in Fig. 1, are in the form of supports 5!, 52 secured to the corestructure 8 near the lower side thereof at opposite sides of thevertical axial plane of the machine. The support 5! at the rear side ofthe machine is shown as a casting or stamping having seating shoulders58, 5d engaging the stator core 8 on opposite sides of a peripheralenlargement H of the core, the element 5| preferably extending acrossthe full length of the core and over or into engagement with the endheads 1, and being secured to the core and end heads as by weldingthereto. This element 5| is provided with a substantially horizontallyextending projection 56 disposed at a point located centrally betweenthe ends of the stator core, and this projection 56 is provided with athreaded aperture.

A supporting element 52 is disposed in position on the core 8 at thefront side thereof and is secured in position to the core and end headsin the same manner as described with respect to the element 5!. Thiselement 52 is provided adja cent each end with horizontal projections51, 58 extending outwardly from the body portion of the element. Thecentral portion of the element 52 is hollow, as indicated at 59,providing a space for reception of leads from the stator winding, theseleads being brought out through a detachable conduit outlet connection6|.

The under side of the supporting lugs or projections 56, 5?, 58 areprovided with machined faces. The base l'l is provided with apertures 53for reception of supporting bolts or studs 64, the latter fitting fairlyclosely, but still being slidable, in the apertures 63. The upper end ofeach stud 64 is of reduced diameter and threaded, providing a shoulder65 which, when the reduced end portions of the studs are threaded intothe apertures of the seating projection 56, 5?, 58, the shoulder sitssolidly against the under side of the projection. Once the stud 64 isscrewed into normal position, with the shoulder 65 of the stud bearingfirmly against its seat on the lower face of the supporting lug, thestud may be held securely in this position in any suitable manner. Anadjusting nut 6"! is provided on each stud 65 above the base, and alocking nut 68 is also provided on each stud below the base.

With the adjusting nut seating on the uppersurface of the base, it actsas a support for the stud and stator connected thereto; and the lockingnut 68, when turned up against the under side of the base, secures thestud and parts carried thereby in adjust'ably fixed position.

With the stator supporting arrangement of Figs. 4 and 5, it will beapparent that each of the supporting studs 64 may be adjustedindependently, through its adjusting nut 67 and locking nut 68, tosecure any desired suitable positioning of the stator and air gapclearance. 1

While but a single supporting lug 5135 is provided at the rear of themotor, thus providing, in corn junction with the two supporting lugs 51,5 3 at the front side of the motor, a three point support for the statoron the base li it will be apparent that a four point support may asreadily be secured, by providing two supporting lugs, instead of thesingle supporting lug 56, at the rear side of the motor, these lugsbeing spaced apart in the same manner as the lugs 51, 58 on thesupporting element 52 at the front side of the motor. I

As described in connection with Figs. 1 the external surfaces of thesupporting elements 5!, 52, in the path of the streams of ventilatingair entering through the annular end frames or closures 2d and passingover the protecting shields l3 and the stator core, are round-ed alongsmooth curves, and the adjustable supporting nuts ii! are preferably ofannular cross section, so as to present a minimum of obstruction to theflow of such ventilating currents and to avoid pockets in which lint anddust may accumulate and build up.

With the described arrangement, it will be apparent that the stator issupported in adjustably fixed position on the base and in desired spacedrelation thereto, to provide for a maximum freedom of flow ofventilating air about all parts of the stator and through a path whichaffords minimum obstruction to such flow, with the advantage that themachine, in operation will be practically self-cleaning, as in the caseof the machine of Figs. 1 and 2, in the matter of carrying along withthe air streams any lint or dust particles suspended therein.

In Figs. 6 and '7, a further modified form of stator support is shown.drawings, the stator supports include supporting elements II in the formof wedgelike braces extending between the end heads '5, each having itslongitudinal edges beveled to fit against the opposing sides of twoadjacent peripheral enlargements II at the lower side of the core, andthe supporting elements being secured in position on the core, as bywelding the edges of such elements to the adjacent portions of the coreand end heads. Each supporting element is provided with two threadedapertures 13, spaced in the direction of the axis of the machine, whichmay extend into the material of the core, the apertures having theiraxes substantially in radial planes of the core. The outer faces of thesupporting elements 'H are preferably provided with machined seats inthe vicinity of the apertures, and these seats are preferably portionsof a cylindrical surface described about the axis of the machine as acenter.

The forward and rear edges of the base li at the central portion thereofmay extend upwardly to a slight extent, as indicated at "5 and the outeredges of these extensions extend downwardly, providing a hollow spacebeneath.

and 2, .4

As indicated in the lower ends of the studs.

These portions 15 are each provided with two supporting pedestals 16,preferably of cylindrical outline, and each having its axis in a radialplane of the machine, the positioning and spacing of the pedestals beingsuch as to correspond with the apertures '53 in the supporting elements1| of the stator. The ends .of the pedestals adjacent the stator aremachined to provide seating surfaces similar to the correspondingseating surfaces on the supporting elements H about the apertures '13therein.

The stator is secured in position on the pedestals l6 and in desired.spaced relation to the base through bolts or studs It passing freel-ythrough, but preferably with a fairly close fit in, the supportingpedestals l6 and threaded into the apertures 13 of the supportingelements H, as by a nut 19 fixed on the lower end of the stud andserving as a head therefor, so that the supporting elements can be drawninto and secured in desired seating engagement upon the correspondingpairs of pedestals 16. Minor adjustments of the seating position of thestator on the base, so as to insure uniform air gap, may be secured byinserting shims about the bolts 18 between the pedestals l6 and thesupporting elements H. l

As a matter of facilitating commercial production of the base, with itssup-porting pedestals 1B, the base may be cast or pressed without thepedestals, apertures being provided at the points corresponding to thedesired positions of such pedestals. And the pedestals, in the form ofsleeves, may have their lower ends secured, as by welding, as indicatedatBt to the adjacent portions of the base, in desired position withinthese apertures, with the extreme lower end of the pedestals protrudingslightly beyond the material about the apertures in the base. Withlimited clearance below the pedestals, the studs 18, without heads, maybe inserted downwardly through the hollow pedestals after the same aresecured in position on the base, and adjusting nuts 19 then pinned orotherwise secured to the Or, as shown in Fig. 8, bolts 78*, withintegral heads 19*, may be used; and in this latter case, these boltstil with their heads of such size as to readily pass through theopenings in the base portions 75 in which the pedestals are secured, maybe inserted in the pedestals before the pedestals are mounted andfixedly secured, as by welding, as indicated at 8!, in position on thebase.

The matter of assembling and disassembling the machines of Figs. 4, 5,6' and 'l andthe paths of the ventilating air streams therethrough willbe fully apparent from the description hereinabove in connection withthe machine of Figs. 1 and 2 as to corresponding features of suchmachine.

Through use of features of the present invention, it is possible toprovide an efficiently ventilated dynamo-electric machine whereinminimum obstruction or hindrance is offered to the passage ofventilating air and there is minimum tendency of lint or dust carried bythe air becoming lodged on parts of the machine and thus interferingwith the desired heat dissipating efiects, and wherein maximum facilityis provided for inspecting, repairing and cleaning parts of the machine,and, in many cases, even without taking the machine out of operatingservice.

It should be understood that the invention claimed is not limited to theexact details of desi n and construction illustrated and describedherein, for obvious modification within the scope of the appended claimswill be apparent to persons skilled in the art.

It is claimed and desired to secure by Letters Patent: I

1. In combination in .a dynamo-electric machine, a supporting basehaving apertured annular end frames carried thereby and integraltherewith and constituting a portion oi housing for the machine, astator element detachably mounted on said base at spaced points ofsupport thereon and wholly at the lower side of said stator, the lowersurface of said stator element and the upper surface of said baseconstitutin a ventilating space extendingthroughout the .major portionof the distance from front to of said base, a rotor element Within saidstator element and rotatably mounted on said end frames and removableaxially from operative position through one of said apertured endframes, said stator element being mounted on said base independently ofsaid end frames and being bodily removablefrom the space between saidend frames through movement of the stator in a direction transverse tothe axis of the machine, and means associated with said rotor forforcing a cooling gas through said space between said stator element andsaid base and about said stator element.

2. In combination in a dynamo-electric machine, a supporting base havingupward extensions adjacent its ends carrying annular end housing frames,bearing supports detachably mounted in said end housing frames, a statorelement detachably mounted in position on the central portion of saidbase on spaced raised seats thereon and independently of said endhousing frames and providing a spaced relation of said stator element tosaid base over the major portion of the periphery of said stator elementadjacent said base, said stator element being disposed axially withinsaid end housing frames and being bodily removable upwardly from saidbase to a point outside of said end housing frames, While said endhousing frames are in normal position on said base, and a rotor ele mentwithin said stator element and rotatably supported in bearings carriedby said bearing supports, said rotor being removable endwise from Withinsaid stator element through an end mounted in said end housing frames, astator element detachably mounted in position on the central portion ofsaid base at spaced points thereon and independently of said end housingframes and providing a'spaced relation of said stator element to saidbase over the major portion of the periphery of said stator element adjacent said base, said supporting base with its end housing frames beingopen at the upper side thereof to permit bodily removal of said statorelement from operative position by movement of said stator element in anupward direction, a rotor element within said stator element androtatably supported in bearings carried by said bearing supports, saidbearing supports being provided with through apertures, and fan meanscarried by said rotor element and operative to draw air through one ofsaid bearing supports and to force the same over the surface of saidstator element.

4. In combination in a dynamo-electric machine, a supporting base havingupward extensions adjacent its ends carrying annular end housing frames,bearing supports detachably mounted in said end housing frames, a statorelement detachably mounted in position on the cen tral portion of saidbase at spaced points thereon through the intermediary of spaced raisedseats on said base and independently of said end housing frames andproviding a spaced relation of said stator element to said base over themajor portion of the periphery of said stator element adjacent saidbase, said stator element being disposed axially within said end housingframes and being removable from said base to a point outside of saidend'housing frames, a rotor element within said stator element androtatably supported in bearings carried by said bearing supports, saidrotor being removable endwise from within said stator element through anend housing frame after removal therefrom of the bearing support carriedthereby, said bearing support being provided with through apertures andhaving an inwardly extending shield for direct ing air passing throughsaid bearing housing support, and fan means carried by said rotor fordrawing air through said apertures in said bearing support and forcingsaid air between said stator element and said base and over said statorelement.

5. In a dynamo-electric machine, a supporting base having annular endframes integral with end portions of said base and provided withremovable supports for bearings for rotatably supporting the rotor ofthe machine, a stator element mounted in position on said baseindependently of said end frames and disposed over the central portionof said base and between said end frames and in spaced relation to saidbase, said stator element being provided with spaced and aperturedseating portions at its forward and rear sides, said base being providedwith apertured seating pedestals adjacent its forward and rear sides,and headed studs within said apertures of said pedestals and threadedinto the aper tures of said seating portions of said stator element andserving to draw and removably hold said stator element in secure seatingengagement on said pedestals.

6. In a dynamo-electric machine, a supporting base having end framesfixedly connected to end portions of said base and provided withremovable supports for bearings for rotatably supporting the rotor ofthe machine, a stator element mounted in position on said baseindependently of said end frames and disposed over the central portionof said base and between said end frames and in spaced relation to saidbase, said stator element being provided with spaced seating portions atits forward and rear sides, said base being provided with correspondingspaced seating pedestals adjacent its forward and rear sides, saidpedestals being provided with am'ally disposed apertures, the seatingfaces of said pedestals and the cooperative seating portions of saidstator element at one side of the vertical axial plane of the machinebeing at an angle to the corresponding seating surfaces at the otherside of said plane, and means for removably securing said stator elementin position with the seating portions of said element in seatingengagement on the pedestals of said base.

'7. In a dynamo-electric machine, a supporting base having annular endframes fixedly connected to the end portions of said base and providedwith removable supports for bearings for rotatably supporting the rotorof the machine, the stator 7 element comprising a winding and alaminated core carrying said winding and secured between relativelystiff end heads separate and spaced from said end frames, the centralportion of said base being provided with spaced raised seating portionsadjacent its forward and rear edges, said end heads being provided withcorresponding spaced seating portions adjacent the forward and rearsides of the stator element, and means for detachably securing saidstator element in operative position on and in spaced relation to saidbase with the spaced seating portions of said end heads in seatingengagement with the seating portions of said base, said supporting basewith its end frames being open at its upper side to permit bodilyremoval and replacement of said stator element with respect to saidsupporting base by movement of said stator element in a directiontransverse to the axis of rotation of the machine.

8. In combination in a dynamo-electric machine, a supporting base havingend housing frames fixedly connected to the end portionsof said base andprovided with alined apertures, a stator element separate and spacedfrom said end frames and mounted independently thereof in position overthe central portion of said base and in spaced relation thereto, bearingsupports removably mounted in said end frames, a rotor elementcomprising a core mounted on a shaft rotatably carried in bearingsmounted on said supports, removable end closures mounted on said endframes and projecting inwardly over extending end portions of saidstator element and spaced throughout from said stator element, and fanmeans mounted on said rotor operative to provide a circulation of airwithin said end closures and over the entire exterior of said statorelement.

9. In combination in a dynamo-electric machine, a supporting base havingend frames fixedly connected to the end portions of said base andprovided with alined apertures, a stator element comprising a coreprovided with windings having projecting end turns, said stator elementbeing detachably mounted in position over an intermediate portion ofsaid base and in spaced relation thereto, apertured bearing supportsremovably mounted in said end frames, a rotor element comprising a coremounted on a shaft rotatably carried in bearings on said bearingsupport, removable closures mounted on said end frames and removablyattached to end portions of said base and projecting inwardly over theextending end portions of said stator to a point adjacent said statorcore and spaced throughout from said stator, said removable closures incom junction with the adjacent end portions of said base enclosing theprojecting end turns of said winding over the full circumferencethereof, and means mounted on said rotor at each side of the corethereof and operative to provide a circulation of air inwardly throughthe openings in said bearing supports and about the radially inner andouter surfaces of the end portions of said stator and to discharge saidair outwardly from the stator core.

10. In combination in a dynamo-electric machine, a supporting basehaving annular end frames fixedly connected to the end portions of saidbase and provided with alined apertures, a

stator element comprising a core provided with windings havingprojecting end turns, said stator element being detachably mounted inposition over an intermediate portion of said base and in spacedrelation thereto and independently of said end frames, bearing supportsremovably mounted in the apertures of said end frames, a rotor elementcomprising a core mounted on a shaft rotatably carried in bearingsmounted on said bearing supports, removable closures mounted on said endframes and projecting inwardly over the extending end portions of saidstator element to a point adjacent said stator core and spacedthroughout from said stator element, and fan means mounted on said rotorat each side of the core thereof and operative to provide a circulationof air about the radially inner and outer surfaces of the end portionsof said stator element and to discharge said air outwardly from thestator core.

11. In combination in a dynamo-electric machine, a supporting basehaving annular end frames fixedly connected to the end portions of saidbase and provided with alined apertures, a stator element comprising acore provided with windings having projecting end turns, protectingshields of substantially U-shape in cross section enclosing saidprojecting end turns, said stator element being detachably mounted inposition independently of said end frames and disposed over the centralportion of said base and in spaced relation thereto, the means formounting said stator on said base comprising spaced pedestals on one ofsaid parts adjacent the front and rear sides thereof and engaging anddetachably secured to correspondingly spaced seating portions on theother part, the cross'section of said pedestals and the spacing thereofheir; such as to permit passage of air axially across substantially thefull periphery of said stator adjacent said base, apertured bearingsupports rei'novably mounted in said end frames, a rotor elementcomprising a core mounted on a shaft, said shaft being mounted inbearings carried by said hearing supports, said rotor element being of amaximum diameter less than the diameter of the opening in one of saidend and being removable through said end frame on removal of the bearingsupport therefrom, removable closures mounted on said end frames andprojecting inwardly over said protecting shields for the stator windingto a point adjacent the stator core and being spaced at all points fromthe stator element, and fan means mounted on said rotor and operative toprovide a circulation of air inwardly through the apertures in saidbearing supports and about the radially inner and outer surfaces of saidprotecting shields and over all portions of the outer periphery of saidstator core.

12. In combination in a dynamo-electric machine, a supporting basehaving end frames integral with the end portions of said base andprovided with alined apertures, the end portions of said base adjacentsaid end frames rising upwardly above the body portion of said base atthe forward and rear sides of the base, a stator element comprising acore provided with windings having projecting end turns, said statorelement being detachably mounted in position on said base independentlyof said end frames and disposed over the central portion of said baseand in spaced relation thereto throughout, apertured bearing supportsremovably mounted in said end frames, a rotor element comprising a coremounted on a shaft, said shaft being mounted in bearings carried by saidbearing supports, arc-shaped removable closures mounted on said endframes and detachably secured to said upwardly rising end portions ofsaid base and projecting inwardly over the extending end portions ofsaid stator to a point adjacent the stator core and being spaced at allpoints from the stator element, said removable end closures inconjunction with the adjacent upwardly extend-- ing end portions of thebase enclosing the end portions of said stator element over the fullperiphery thereof, and fan means mounted on said rotor and operative toprovide the circulation of air inwardly through the openings in saidbearing supports and about the radially inner and outer surfaces of theend portions of the stator and over all portions of the outer peripheryof the stator core, and to discharge said air out- Wardly from thestator core at all points.

13. In a dynamo-electric machine, a supporting base, a stator elementhaving extending end portions and removably mounted in fixed positionover an intermediate portion of said base in spaced relation thereto,one of said parts being provided with a plurality of seating pedestalsdisposed at its forward and rear portions, and the other part beingprovided with correspondingly spaced seating portions, the front andrear edges of said base at said intermediate portion thereof being opento provide access to the space between said base and said statorelement, end portions of said base at the front and rear si :3 thereofbeing provided with integrally formed upwardly extending curved wallsgradually merging into the adjacent portion of said base, and annularend frames having integrally formed curved lower portions whichgradually merge into the adjacent portions of said base and saidupwardly extending walls rising from the end portions of said base,bearing housings detachably mounted in the openings of said end frames,a rotor comp-rising a core mounted on a shaft rotatably mounted inbearings carried by said bearing housings, and arc-shaped end closuresremovably supported on said end frames and upwardly extendingprojections at the end portions of the base and projecting over andspaced from the extending end portions of said stator.

14. Ina dynamo-electric machine, a supportmg base, a stator elementhaving extending end portions and removably mounted in fixed positionover an intermediate portion of said base in spaced relation thereto,one of said parts being provided with a plurality of seating pedestalsdisposed at its forward and rear portions, and

the other part being provided with correspond ingly spaced seatingportions, the front and rear edges of said base at said intermediateportion thereof being open to provide access to the space between saidbase and said stator element, end portions of said base at the front andrear sides thereof being provided with integrally formed upwardlyextending curved walls gradually merging into the adjacent portion ofsaid base, and annular end frames having integrally formed curved lowerportions which gradually merge into the adjacent portions of said baseand said upwardly extending walls rising from the end portions of saidbase, bearing housings detachably mounted in the openings of said end arotor comprising a core mounted on a shaft rotatably mounted in bearingscarried by said bearing housings, arc-shaped end closures removablysupported on said end frames and said upwardly extending projections atthe end portions of the base and projecting over and spaced from theextending end portions of said stator, and fan means mounted on saidrotor at each side thereof and operative to cause a circulation of airinwardly through openings in said end frames and thence about theextending end portions of saidstator element.

15. In combination in a dynamo-electric machine, a supporting basehaving spaced end housing frames of unitary construction therewith, astator element comprising a core and windings thereon, said statorelement being detachably mounted on said base in spaced relation theretoand intermediate and independently of said end frames, said supportingbase with its end housing frames being open at the upper side thereof topermit bodily removal of said stator element from operative positionthrough movement of said stator element in a direction transverse to theaxis of rotation of the machine, a rotor element within said statorelement and rotatably mounted in said end frames, and means for causingcirculation of cooling gas about the extending end portions of thewinding of said stator element and through the space between said statorelement and said base.

16. In combination in a dynamo-electric machine, a supporting basehaving spaced end housing frames of unitary construction therewith, astator element comprising a core and windings thereon, said statorelement being detachably mounted on said base in spaced relation theretoand intermediate and independently of said end frames, said supportingbase with its end housing frames being open at the upper side thereof topermit bodily removal of said stator element from operative positionthrough movement of said stator element in a direction transverse to theaxis of rotation of the machine, a rotor element within said statorelement and rotatably mounted in said end frames, end shields detachablymounted on said end frames to close the opening in the upper portionthereof and serving therewith to provide an enclosure for the extendingend portions of the stator winding and spaced from said stator elementthroughout, and means for causing the circulation of cooling gas aboutthe extending end portions of said stator element and through the spacebetween the latter and said base.

1'7. In combination in a dynamo-electric machine, supporting meanshaving spaced end housing frames thereon, a stator element comprising acore and windings thereon, said windings extending axially within saidend housing frames, said stator element being detachably mounted on saidsupporting means in spaced relation to and independently of said endframes and above the portion of said supporting means intermediate saidend frames, said end housing frames being open at the upper side thereofto permit bodily removal of said stator element from operative positionby upward movement of said stator element, a rotor element within saidstator element and rotatably mounted in said end frames, and means forcausing the circulation of cooling gas about the extending end portionsof the winding of said stator element and through the space between thelatter and said supporting means.

18. In combination in a dynamo-electric machine, supporting means havingspaced end housing frames thereon, said stator element comprising a coreand windings thereon, said stator element being mounted on saidsupporting means in spaced relation thereto and intermediate andindependently of said end frames, a portion of the windings of saidstator element projecting axially within said end housing frames, andsaid end housing frames being open at the upper side thereof to permitbodily removal of said stator element from operative position bymovement in a direction transverse to the axis of rotation of themachine, a rotor element within said stator element and rotatablymounted in said end frames, end shields detachably mounted on said endframes to close the openings in the upper portion thereof and servingtherewith to provide an enclosure for the extending end portions of thewinding of said stator element and spaced from said stator elementthroughout, and means for causing the circulation of cooling gas aboutthe extending end portions of said stator element and through the spacebetween the latter and said supporting means and end shields.

19. In combination in a dynamo-electric machine, a supporting basehaving spaced end housing frames mounted thereon, a stator elementcomprising a core and windings thereon and detachably mounted on saidbase in spaced relation thereto and independently of said end frames,extending end portions of said winding projecting axially within saidend housing frames, and said supporting base with its end housing framesbeing of open construction at the upper side thereof to permit bodilyremoval and replacement of said stator element with respect to saidsupporting base through movement of said stator element in a directiontransverse to the axis of rotation of the machine, a rotor elementrotatably mounted in bearings carried by and removable from said endframes, and means associated with said rotor element for providing acirculation of cooling gas about the extending end portions of saidstator element and through the space between said stator element andsaid base.

20. In a dynamo-electric machine, a unitary supporting structurecomprising spaced end housing frames and a base portion intermediatesaid frames, a rotor operatively mounted in bearings carried by said endhousing frames, and a stator element surrounding said rotor andcomprising a core and windings carried thereby, said windings having endextending portions projecting axially within said end housing frames,and said stator element being disposed over said base portion andmounted in operative position thereon independently of said end housingframes and being in spaced relation to said base portion throughout themajor portion of the distance between the front and rear of said baseportion, said supporting structure, including the end housing framesthereof, being open at the upper side to an extent to permit bodilyremoval of said stator element from operative position by movement in adirection transverse to the axis of rotation of the machine, and meansfor forcing a cooling gas about the periphery of said stator element andbetween the latter and said base portion.

21. In combination in a dynamo-electric machine, a supporting baseprovided at the end portions thereof with apertured bearing supportingend housing frames, a rotor operatively supported in bearings in saidend housing frames, a stator surrounding said rotor and mounted inoperative position over and in spaced relation to an intermediateportion of said base wholly through spaced cooperative supportingportions on said base and the lower side of said stator, said statorbeing free of engagement with and spaced from said end frames, and saidrotor being removable from within said stator through one of saidapertured end housing frames, and said base and end housing frames beingopen at the upper side thereof to an extent to permit bodily removal ofsaid stator element from operative position by upward movement of thestator element past said end housing frames.

EARLE R. KNIGHT.

